Maj Dad
Member
It's kind of like feeling your way down a dim hallway - you start out with the closest landmark, then try to look beyond. I get on paper in at 25, start with rough load testing at 50 yds, then move to 100 to fine-tune (our range has only a 100 yd rifle range). In New Mexico we had a 200 and 400 yd ranges, and I routinely sighted in at 200; accurate loads at 200 all did well at 400 for me. You can infer that an accurate 25 yd load is accurate at 100, but inference is not proof: the proof of the pudding is the eating thereof... 
